Drinking vessel accessory



FIG. 1 is a top perspective view of a drinking vessel accessory showing the new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a first side elevation view thereof;

FIG. 4 is a second side elevation view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

CLAIM The ornamental design for a drinking vessel accessory, as shown and described. 